Cofferdam



5- PERKINS COFFERDAM 2 SHEETS-SHEET 1 Filed Aug. 29, 1947 s l l I l I l l l l 11 b R Ii m w MP l Ll A m Ln 9 1 I n u n W T. |rl| "Huh" 5 ATTORNEYS S. PERKINS COFFERDAM May 13 1952 2 SHEETS-SHEET 2 Filed Aug. 29, 1947 WWW ./I a F A TTORNEYS Patented May 13, 1952 UNITED STATES PATENT QFFIGE Y p asesnss COFFEBDAM I Starling Perkins, Chouteau, Okla.

Application August 29', 1947, Serial No. 771,269 I (01. 61-82) v 2 Claims.

assemble, require the workmen to operate under high pressures, and are difilcult and oftentimes impossible tosalvage when the work is completed.

It is, therefore,the principal object of the present invention to provide a relatively simple structure for any cofier-dam use and which is composed of readily interconnected sections that may be readily handled and shipped to a site of operations for simple assembly and which sections are equipped with excavating jets and other equipment to effect placement of the coffer-dam and operations that are to be performed therewith. -Other objects of the invention are to maintainthe'flow of pressure fluids after the cofferdam is in position to prevent entrance of external fluids while the soil is being removed from the interior of the cofier-dam; to provide a coffer-dam structure wherein the weight thereof is supplemented by weight of liquids adapted to be injected within the compartments of the respective sections and from which the liquids are adapted'to be pumped for controlling sinking of the coffer-dam; to provide a coder-dam with means for freezing the soil and fluids at the base thereof to assist in drying up the interior so that the soil may be excavated and the desired structures built therein; and to provide a coffer-dam constructed to facilitate ready removal thereof after the work has been completed.

In accomplishing these and other objects of the invention hereinafter pointed out, I have provided improved structure, the preferre'd'form of which is illustrated in the accompanying drawings wherein:

Fig. 1 is a vertical sectional view through a coifer-dam constructed in accordance with the s present invention and showing the manner of sinking the coffer-dam structure into an earth formation. 1 Fig. 2 is a detail fragmentary view through adjacent sections of the coffer-dam, illustrating the interlocking connection thereof.

. Fig. 3 is a fragmentary perspective sectional view through one of the cotter-dam sections, particularly illustrating the construction thereof.

. Fig. 4 is a section through a modified form of v the invention showing refrigerating coils in the .lower compartment. .iReferring more in detail to the drawings:

I. designates a coffer-dam constructed in accordance with the present invention and which may be of any suitable cross sectionallshape to conform with the shaft to be sunk into an. earth formation; however, the coffer-dam is preferably of cylindrical shape and the wall structuremay comprise two or more sections depending upon the size of the dam. For example, in the illustrated instance, the coffer-dam comprisesa pair of semi-cylindrical sections 2 and 3 joined at opposite diametrical sides of the dam by interlocking slidable connections 4 later described. Each section includes an inner wall sheetipreferably composed of sheet metal in semi-cylindrical shape to form the inner contour of the coi'I'er-dam.

Extending along the outer side of the inner wall 5 are a plurality of vertically spaced angles 6, 1,8, and 9 which are shaped to conform with the outer contour of the inner wall and which have horizontal flanges H), H, l2, and [3 respectively. The flanges I0 and I3 of the upper and lower angles 6 and 9 are welded or otherwise suitably attached to the upper and lower edges of the inner wall and the intermediate angles '3 and 8 have the horizontal flanges II and I2 thereof similarly welded to the inner wall to provide leak-tight joints. The other legs l4, l5, l6 and ll of the respective angles extend downwardly in spaced relation with the inner wall for attaching an outer wall sheet I8 which is preferably composed of a plurality of segmental rings I9, 20, 21 and 22 having the upper and lower edges in abutting relation and overlapping-the flanges l4, l5, l6 and ll of the respective angles so that the edges of the plates may be welded together and to the flanges to provide leak-tight joints between compartments 23, 24, and 25 that are provided between the respective angles.

The connections 4 each include mating members 26 and 21' of substantially corresponding shape but arranged reversely with respect to the positions they occupy in the respective sections of the cofier-dam. Each member of an interlocking connection comprises a transverse plate portion 28 of sufiicient width to extend across'the space between the inner and outer walls of the coffer-dam sections for closing the ends of the respective compartments. Coextensive with one side of the transverse plate 28 is a flange portion 29 that extends laterally therefrom and has a coextensive rib portion 30 on its outer edge and extending in the same direction and parallel with the plate portion 28. The rib 30 is spaced from the 'plate portion 28 to provide a channellike groove 3| extending from the flange iii of the lower angle member to the flange I3 of the upper angle member. Also extending laterally from the plate portion 28 intermediate the ends thereof, in the same direction and substantially parallel with the flange 28 is a tongue portion 32 havinga T-shaped'head portion 33 that is coextensive with the rib portion 30 and is spaced therefrom to provide a vertical slot-like way 34. The head 33 thus cooperates with the tongue 32 to form vertical grooves 35 and 36 on opposite sides thereof in lateralalignment with the groove 3|. The connection'member thus described has a cross section substantially the shape of the letter F and the complementary connecting member is reversely arranged with respect thereto so that the flange portion 29 of one member is adapted to be welded to the inner face of an extension of the outer wall member of one cofferdam section and the corresponding flange of the other member is welded to an extension of the inner wall of the other cotter-dam section. The opposite side edge of the plate portions of the connecting members are respectively welded to the inner and outer: walls of the respective, adjacent. ends of the coffer-dam section as clearly shownin Fig. 2. They ends of. the compartments are thus closedfromteachother and consequently each cofier-dam section must be provided with its own supply ductsand manifolds as later de scribed;

Suitable clearance is preferably providedbetweenthe interlocking portions. of the respective connecting; members, so that the joints. may be filled. with a heavy grease. to facilitate sliding movement of the cotter-dam sections relatively to eachother when the sections are to be removed as; later described. The grease also retards leakage: through the joints and prevents infiltration of external pressure fluids.

The flange I4 of the. lower angle member depends. downwardly andcooperates with the lower edge, of the lowermost plate of the outer Wall to provide acutting edge 3-! which may be reinforced onthe inner side of. the leg [4 by a plate 38 as best shown in Figs. 2 and 3. The plates forming the Wall portion closing the outer side of the lower compartments 23. have a plurality of. apertures 39 that are covered on the inner side by a plurality of. layers preferably of noncorrosive wire screen 40 that are retained in position by a cover plate 41 having apertures 42 registering with the apertures 39 as best shown in. Fig. 2. The plate 44. is preferably weldedin position asv indicated at 43; The lower portion ofthe; inner wall sheet of each coiTer-dam section is provided with a plurality of similar apertures: 44 covered by layers of screening 45 that are retained inposition on the inner side of the wall. sheet by an apertured retaining plate 45. Theapertures 44' are located: adjacent the lower edge of the inner wall sheet and the other row of apertures terminate below the upper row of theapertures in the outer wall sheet so that all of the apertures 44' connect with a duct. 41 that is formed within the compartment sS-by an angle 48 having a horizontal flange d9 welded to the inner wall sheet above the upper row of openings and having a. vertical flange 50 welded tothe top face of the horizontalfiange lilas shown in Fig. 2. The duct extends thev full length of the respective cotter-dam sections and has. its ends closed by the plate portions 2.8 f the respective connecting members. i

The ducts thus formed are. supplied. with a pressure fluid through a duct 5| that extends upwardly through suitable openings in the re spective flanges l1, l2 and 13 and which has a threaded terminal 522 that is adapted'to baconnected by a suitable duct. 53 leading to a source of supply. Also formed in the compartment 23 and supported upon the flange l0 immediately adjacent the outer wall of each coffer-dam section is a duct 54 having a plurality of apertures 55 through which a pressure fluid is discharged into the chamber for outlet through the outer openings 40 as later described. The: perforated duct 54 is supplied with pressure fluid through a duct 56 leading upwardly through the flanges ll, 12 and 13 which is connected with a supply duct-51.

The compartment 23 is connected with the compartment 25 by a duct 58 having its ends Welded in suitable openings formed in the flanges l l and I2 as indicated at 59 and 60 (Fig. 3) The compartments 25 and 23 of each cofier-dam section are thus interconnected for flow of a liquid therebetween as later described. Each compartment. 23 is. also provided with an air jet: pump indicated at M (Fig. 3) to which is connected an air supply duct .62 and a liquid discharge duct 63 which .ducts extend upwardly through suitable openings. inthe flanges H, I2 and i3 and adapted to be connected through. ducts. 64 and 65 respectivelyleading to a source of. air. supply and aliquid disposal, the pump 6| being. used for a purpose later described.

Thenext upper compartment 24. of each-cofferdam section has theouter wall thereof provided with a plurality of jet openings 66 covered on the innerface of the; wall by a plurality of layers of screen 6'! that. are retained in position by a plate 68. having: apertures 69. The plate 68;ispreferably weldedin position similar to the other plates previously described.

The compartment 24: is also provided with a duct 10 that is supported on the flange H ad.- jac'ent the outer wall and which is provided with a plurality of jet outlets H. Each duct l0 is supplied witha pressure fluid through. a duct, 12 that extends upwardly throughsuitable openings in the flanges l2 and; I3- respectively to be connected with an extension duct 73. Thev upper compartment 25 is adapted to be connected: with anextension duct 14 which, is secured to av nipple iii-mounted in the flange l3 and which discharges into thecompartment 25. as, best shown in Fig.3; Thefiange Him the upper'angle-member of each section may be provided; with a spacedseries of bolts 16 having upwardly: extending. shanks H to. which. are connected inturned flanges 18 of caissonplate sections-l9 having flange side edges and 8| adapted to be connected by slip joints similar to the sliding joints of the coffer-dam sections or which are adapted to be clamped-together by bolts. 82 to form a. caissonv which is lowered with the coifer-dam. The caisson sec;- tions, may be added to so that they extend to the top ofthe formation and form an enclosure through which the soil within the coffer-dam is excavated upon final setting. of the cotter-dam.

In using the coifer-dam; the sections are-transportedv to. the site of operations. and one. section is stood in vertical position with the lower'cutting edge thereof supported on the surface oftthe ground, for example, on the bed of a stream'into which the cofier-d'am is to, be placed and' the other sectionissupported in; proper; relation 'so that-the T-shaped flanges and ribs of the connecting' members of onesectiorr register. with the grooves of the complementary connecting; members ofv the other section whereupon the section is lowered into position until; the. cutting dge thereof also rests upon the. bed of" the. stream. The sections. when thus related. form" av circular coffer-damwhich'encirclesthe site oftheshaft to be excavatedi I The caisson extensions may be applied and secured to the sections thus placed by the bolts 16. The duct extensions 13 and 51 are connected with the projecting threaded ends of the ducts i2 and 56 of each coiTer-dam section so that liquid under pressure may be discharged into the chambers 23 and 24 from which the liquid is discharged under pressure through the jet openings for flow upwardly alongside the outer wall of the coffer-dam sections to displace and move upwardly the soil into which the cofierdam is to be sunk. Simultaneously jets of liquid may be discharged through the openings 44 to effect a similar upflow of liquid and soil along the inner wall 5. The compartments 23, 24 and 25 fill with liquid which adds weight in cooperation with the excavating action of the jets to effect sinking of the coffer-dam to its desired position. When the cofier-dam isin its desired position air under pressure is admitted through the pipe extension 14 for displacing the water from the upper compartment 25 and into the lower compartment through the pipe 58 and from the lower compartment through the apertures 40. As the compartments empty the air is discharged through the jet opening to hold back the external liquids which might tend to pass under the cofier-dam. Similar jets of air may be discharged 'through the openings 44 into the interior of the coffer-dam and the water may be pumped from the interior of the coifer-dam by any suitable means (not shown) to dry up the core. The air pressure may be maintained while the soil of the core is being excavated to permit installation of a pier or other structure for which the shaft is formed. In case of a concrete pier, the form may be constructed within the cofferdam and the concrete poured, after which the coffer-dam sections may be raised by lifting one of the sections out of interlocking relation with the other section. The other section may then be removed so as to permit the formation to settle in and around the pier as the sections are raised for reuse at another site of operations.

The construction shown in Fig. 4 corresponds with the structure as above described but the lower compartment 23 is provided with suitable refrigerating coils 83 to freeze the liquids immediately surrounding the lower edge of the coffer-dam sections to further prevent leakage of external water into the coffer-dam and further assist in drying out of theinterior formation to facilitate removal thereof.

A cofier-dam constructed as described has many uses such as the sinking of wells in which case the pump 6| may be used for removing water which flows from the water producing formation into which the coifer-dam is sunk into the compartment 23 through the apertures 46 and 44. The coffer-dam may also be used for the sinking of oil and gas wells through loose earth formations to the solid formations. It may also be used as an agitator for dredging.

While I have described the coffer-dam as operatingin a vertical direction, it is also obvious that it may be turned on its side for lateral tunneling. It is also obvious that the coffer-dam may be constructed in various shapes and sizes and composed of as many interlocking sections as desired without departing from the spirit of the invention.

From the foregoing it is obvious that I have provided a cofier-dam structure that is of simple and inexpensive construction for the removal of the interior formation without the use of pressure chambers, air locks and the like.

What I claim and desire to secure by Letters Patent is:

1. An apparatus of the character described including a wall forming a coifer-dam, said wall having inner and outer sheets and horizontally arranged connecting members spaced apart and interconnecting the inner and outer sheets to form separate inner compartments one above the other with the upper compartment being closed and the lower compartment having outlets in the outer sheet for discharge of pressure fluids from the lower compartment, means for supplying liquid under pressure to the lower compartment for discharge through said outlets to efiect sinking of the wall in a soil formation, a flow connection between said compartments for supplying liquid to the upper compartment to add weight to the wall for facilitating sinking thereof, means within the lower compartment for cooperating with the inner sheet for forming a duct separate from the compartment and said inner sheet having apertures in direct connection with the duct, means for supplying a pressure medium to said duct means separate from the liquid supply means to retard flow of liquid tending to flow under said wall and into the coffer-dam, and means connected with the upper compartment for introducing air under pressure to said compartment for displacing said liquid to control sinking rate of the wall.

2. An apparatus of the character described including a wall forming a coffer-dam, said wall having inner and outer sheets and horizontally arranged connecting members spaced apart and interconnecting the inner and outer sheets to form separate inner compartments one above the other with the upper compartment being closed and the lower compartment having outlets in the outer sheet for discharge of pressure fluids from the lower compartment, means for supplying liquid under pressure to the lower compartment for discharge through said outlets to effect sinking of the wall in a soil formation, a flow connection between said compartments for supplying liquid to the upper compartment to add weight to the wall for facilitating sinking thereof, means within the lower compartment for coopcrating with the inner sheet for forming a duct separate from the compartment and said inner sheet having apertures in direct connection with the duct, and means for supplying a pressure medium to said duct separate from the liquid supply means to retard flow of liquid tending to flow under said wall into the coifer-dam.

STARLING PERKINS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 732,401 Dungan June 30, 1903 927,963 Gibbs July 13, 1909 1,024,822 Bignell Apr. 30, 1912 1,563,676 Turner Dec. 1, 1925 1,905,643 Johnson Apr. 25, 1933 FOREIGN PATENTS Number Country Date 455,375 France 1913 

